U.S. patent application number 14/003739 was filed with the patent office on 2014-03-06 for wind turbine.
This patent application is currently assigned to WILIC S.AR.L. The applicant listed for this patent is Matteo Casazza, Alessandro Fasolo, Otto Pabst. Invention is credited to Matteo Casazza, Alessandro Fasolo, Otto Pabst.
Application Number | 20140062231 14/003739 |
Document ID | / |
Family ID | 43977044 |
Filed Date | 2014-03-06 |
United States Patent
Application |
20140062231 |
Kind Code |
A1 |
Casazza; Matteo ; et
al. |
March 6, 2014 |
WIND TURBINE
Abstract
A wind turbine having an electric machine, in turn having a
stator, and a rotor which rotates about an axis of rotation with
respect to the stator; the rotor having a plurality of magnetized
modules, and a rotor cylinder which extends circumferentially,
rotates about an axis of rotation, and is configured to support the
plurality of magnetized modules; and wherein the rotor cylinder is
made of nonmagnetic material.
Inventors: |
Casazza; Matteo; (Val Di
Vizze, IT) ; Pabst; Otto; (Rio Di Pusteria, IT)
; Fasolo; Alessandro; (Vipiteno, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Casazza; Matteo
Pabst; Otto
Fasolo; Alessandro |
Val Di Vizze
Rio Di Pusteria
Vipiteno |
|
IT
IT
IT |
|
|
Assignee: |
WILIC S.AR.L
Luxembourg
LU
|
Family ID: |
43977044 |
Appl. No.: |
14/003739 |
Filed: |
March 10, 2012 |
PCT Filed: |
March 10, 2012 |
PCT NO: |
PCT/IB2012/051133 |
371 Date: |
November 11, 2013 |
Current U.S.
Class: |
310/59 ;
310/156.49 |
Current CPC
Class: |
F03D 1/04 20130101; H02K
1/274 20130101; H02K 1/27 20130101; F05B 2220/7066 20130101; H02K
7/1838 20130101; H02K 1/2773 20130101; H02K 1/30 20130101; F03D
15/20 20160501; Y02E 10/72 20130101; Y02E 10/725 20130101; F03D
9/25 20160501; H02K 1/2786 20130101; H02K 5/18 20130101 |
Class at
Publication: |
310/59 ;
310/156.49 |
International
Class: |
H02K 1/27 20060101
H02K001/27; H02K 1/30 20060101 H02K001/30; H02K 9/02 20060101
H02K009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 10, 2011 |
IT |
M12011A000374 |
Claims
1-10. (canceled)
11. A wind turbine electric machine comprising: a stator; and a
rotor configured to rotate about an axis of rotation with respect
to the stator, the rotor including: a plurality of magnetized
modules, a plurality of pairs of magnetic guides, each pair of
magnetic guides coupled to at least a respective one of the
magnetized modules, a rotor cylinder made of a nonmagnetic material
and which: (i) extends circumferentially, (ii) is configured to
rotate about the axis of rotation, and (iii) is configured to
support the plurality of magnetized modules, and a plurality of
supports arranged about and extending radially with respect to the
axis of rotation, said plurality of supports fitted to the rotor
cylinder to: (i) support the magnetized modules, and (ii) support
the pairs of magnetic guides such that the pairs of magnetic guides
are spaced apart from the rotor cylinder.
12. The wind turbine electric machine of claim 11, wherein the
rotor includes a plurality of cooling members arranged about and
extending radially with respect to the axis of rotation, said
plurality of cooling members fitted to the rotor cylinder and
configured to cool the rotor.
13. The wind turbine electric machine of claim 12, wherein the
cooling members extend from an opposite side of the rotor than the
plurality of supports.
14. The wind turbine electric machine of claim 12, wherein the
supports include a plurality of grippers connected to the rotor
cylinder to support the plurality of magnetized modules.
15. The wind turbine electric machine of claim 12, wherein the
cooling members include a plurality of cooling fins configured to
cool the rotor, said cooling fins connected to the rotor cylinder
on an opposite side of the rotor than the plurality of
supports.
16. The wind turbine electric machine of claim 11, wherein the
plurality of supports include a plurality of arms extending
radially with respect to the axis of rotation to support the
magnetized modules.
17. The wind turbine electric machine of claim 16, wherein the
cooling members include a plurality of cooling fins configured to
cool the rotor, said plurality of cooling fins extending radially
with respect to the axis of rotation.
18. The wind turbine electric machine of claim 17, wherein the
cooling fins extend on an opposite side of the rotor than the
arms.
19. The wind turbine electric machine of claim 16, wherein the arms
are made of nonmagnetic material and are coupled to the rotor
cylinder.
20. The wind turbine electric machine of claim 17, wherein the
cooling fins are made of nonmagnetic material and coupled to the
rotor cylinder.
21. The wind turbine electric machine of claim 11, wherein the
nonmagnetic material is one selected from the group consisting of:
aluminum, aluminum alloy, stainless steel, copper, and a polymer
material.
22. The wind turbine electric machine of claim 11, wherein the
rotor includes a plurality of pairs of magnetic guides, each pair
of magnetic guides being fitted to at least a respective one of the
magnetized modules to guide a flux of the magnetized module.
23. A wind turbine electric machine rotor configured to rotate
about an axis of rotation with respect to a stator, said wind
turbine electric machine rotor comprising: a plurality of
magnetized modules; a plurality of pairs of magnetic guides, each
pair of magnetic guides coupled to at least a respective one of the
magnetized modules; a rotor cylinder made of a nonmagnetic material
and which: (i) extends circumferentially, (ii) is configured to
rotate about the axis of rotation, and (iii) is configured to
support the plurality of magnetized modules; and a plurality of
supports arranged about and extending radially with respect to the
axis of rotation, said plurality of supports fitted to the rotor
cylinder to: (i) support the magnetized modules, and (ii) support
the pairs of magnetic guides such that the pairs of magnetic guides
are spaced apart from the rotor cylinder.
24. The wind turbine electric machine rotor of claim 23, which
includes a plurality of cooling members arranged about and
extending radially with respect to the axis of rotation, said
plurality of cooling members fitted to the rotor cylinder.
25. The wind turbine electric machine rotor of claim 24, wherein
the cooling members extend from an opposite side than the plurality
of supports.
26. The wind turbine electric machine rotor of claim 24, wherein
the supports include a plurality of grippers connected to the rotor
cylinder to support the plurality of magnetized modules.
27. The wind turbine electric machine rotor of claim 24, wherein
the cooling members include a plurality of cooling fins connected
to the rotor cylinder on an opposite side than the plurality of
supports.
28. The wind turbine electric machine rotor of claim 23, wherein
the plurality of supports include a plurality of arms extending
radially with respect to the axis of rotation to support the
magnetized modules.
29. The wind turbine electric machine rotor of claim 28, wherein
the cooling members include a plurality of cooling fins extending
radially with respect to the axis of rotation.
30. The wind turbine electric machine rotor of claim 29, wherein
the cooling fins extend on an opposite side than the arms.
31. The wind turbine electric machine rotor of claim 28, wherein
the arms are made of nonmagnetic material and are coupled to the
rotor cylinder.
32. The wind turbine electric machine rotor of claim 29, wherein
the cooling fins are made of nonmagnetic material and coupled to
the rotor cylinder.
33. The wind turbine electric machine rotor of claim 23, wherein
the nonmagnetic material is one selected from the group consisting
of: aluminum, aluminum alloy, stainless steel, copper, and a
polymer material.
34. The wind turbine electric machine rotor of claim 23, which
includes a plurality of pairs of magnetic guides, each pair of
magnetic guides being fitted to at least a respective one of the
magnetized modules to guide a flux of the magnetized module.
Description
PRIORITY CLAIM
[0001] This application is a national stage application of
PCT/IB2012/051133, filed on Mar. 10, 2012, which claims the benefit
of and priority to Italian Patent Application No. MI2011A 000374,
filed on Mar. 10, 2011, the entire contents of which are each
incorporated by reference herein.
BACKGROUND
[0002] One type of known wind turbine includes an electric machine
having a stator, and a rotor which rotates with respect to the
stator about an axis of rotation. In this known wind turbine, the
stator comprises a stator cylinder, and stator segments arranged
about the axis of rotation along the stator cylinder. And,
similarly, the rotor comprises a rotor cylinder, and rotor segments
arranged about the axis of rotation along the rotor cylinder. Each
rotor segment comprises a support extending parallel to the axis of
rotation; and magnetized modules arranged inside the support,
parallel to the axis of rotation. The rotor segments are fitted to
the rotor cylinder, and the stator segments to the stator cylinder.
The rotor cylinder is fitted to the stator cylinder by at least one
bearing, and is connected to a hub and to blades arranged about the
hub.
[0003] German Patent No. DE 10 2009 025929 and PCT Patent
Application No. WO 2006017377 disclose a rotor comprising magnetic
guides and magnetic module and wherein the magnetic guides are
fixed directly to the rotor.
[0004] European Patent No. EP 2282397 discloses a rotor comprising
a magnetic guide and magnetic module supported by supports and
spaced apart from rotor cylinder.
[0005] One known drawback of certain known wind turbines lies in
part of the energy transmitted from the blades to the electric
machine being dispersed in so-called electromagnetic losses,
particularly in the rotor.
[0006] Electromagnetic losses are caused by electromagnetic fields
interacting between the stator and rotor, thus resulting in power
dissipation and a reduction in the efficiency of the electric
machine.
[0007] One particular type of electromagnetic loss originating in
the rotor is caused by the magnetic flux which closes on the rotor,
is produced by the harmonics of the magnetomotive force of the
stator, and induces parasitic currents in the rotor without
producing any drive torque.
[0008] Another problem of certain known wind turbines lies in power
dissipation overheating the component parts of the rotor.
SUMMARY
[0009] The present disclosure relates to a wind turbine configured
to produce electric power.
[0010] More specifically, the present disclosure relates to a wind
turbine comprising an electric machine having a stator, and a rotor
which rotates with respect to the stator about an axis of
rotation.
[0011] It is an advantage of the present disclosure to provide a
wind turbine configured to limit certain of the drawbacks of
certain of the known art.
[0012] A further advantage of the present disclosure is to provide
a wind turbine configured to reduce electromagnetic losses in the
rotor caused by harmonics of the magnetomotive force of the
stator.
[0013] A further advantage of the present disclosure is to provide
a wind turbine configured to reduce overheating of the rotor.
[0014] According to one embodiment of the present disclosure, there
is provided a wind turbine comprising an electric machine, in turn
comprising a stator, and a rotor which rotates about an axis of
rotation with respect to the stator; the rotor comprising a
plurality of magnetized modules, and a pairs of magnetic guides
coupled to at least a respective magnetized module, and a rotor
cylinder which extends circumferentially, rotates about an axis of
rotation, and is configured to support the plurality of magnetized
modules; wherein the rotor comprises supports arranged about and
extending radially with respect to the axis of rotation, and fitted
to the rotor cylinder to support the magnetized modules and the
pairs of magnetic guides; the pairs of magnetic guides are
supported by the supports in such a way that the pairs of magnetic
guides are spaced apart from the rotor cylinder; the wind turbine
being characterized in that the rotor cylinder is made of
nonmagnetic material.
[0015] By virtue of the present disclosure, the magnetic flux
produced by the harmonics of the magnetomotive force of the stator,
and which closes through the nonmagnetic rotor cylinder, is greatly
attenuated with respect to certain of the known art, in which the
rotor cylinder is made of ferromagnetic material. Consequently, the
parasitic currents circulating in the rotor, and power dissipation
are also reduced, thus reducing heating of the rotor.
[0016] In one embodiment of the present disclosure, the nonmagnetic
material is aluminum, aluminum alloy, stainless steel, copper, or
polymer material.
[0017] An aluminum rotor cylinder is a good heat conductor and
extremely lightweight; and an aluminum rotor can be extruded to
form the rotor cylinder, cooling fins and supports simultaneously,
provided the fins and supports are parallel to the rotor axis.
[0018] Additional features and advantages are described in, and
will be apparent from the following Detailed Description and the
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A number of non-limiting embodiments of the present
disclosure will be described by way of example with reference to
the accompanying drawings, in which:
[0020] FIG. 1 shows a side view of a wind turbine;
[0021] FIG. 2 shows a schematic front view, with parts removed for
clarity, of an electric machine of the FIG. 1 wind turbine;
[0022] FIG. 3 shows a larger-scale fragmentary side view, with
parts removed for clarity, of the FIG. 2 electric machine; and
[0023] FIG. 4 shows a larger-scale fragmentary side view, with
parts removed for clarity, of an alternative embodiment of the FIG.
2 electric machine.
DETAILED DESCRIPTION
[0024] Referring now to the example embodiments of the present
disclosure illustrated in FIGS. 1 to 4, number 1 in FIG. 1
indicates as a whole a wind turbine configured to produce electric
power.
[0025] In the FIG. 1 example, wind turbine 1 is a direct-drive,
variable-angular-speed type, and comprises a supporting structure
2, a nacelle 3, a hub 4, three blades 5 (only two shown in FIG. 1),
and an electric machine 6.
[0026] Blades 5 are fitted to hub 4, in turn fitted to nacelle 3,
in turn fitted to supporting structure 2.
[0027] Supporting structure 2 is a structural member supporting
nacelle 3.
[0028] In another variation of the present disclosure (not shown),
supporting structure 2 is a pylon, such as a pylon made of ferrous
material.
[0029] As shown in FIG. 1, nacelle 3 is mounted to rotate about an
axis A1 with respect to supporting structure 2, to position blades
5 into the wind; hub 4 is mounted to rotate about an axis of
rotation A2 with respect to nacelle 3; and each blade 5 is fitted
to hub 4 to rotate about an axis A3 with respect to hub 4. Electric
machine 6 comprises a stator 10, and a rotor 11 which rotates with
respect to stator 10 about axis of rotation A2. And hub 4, blades
5, and rotor 11 define a rotary assembly 12, which rotates with
respect to nacelle 3 about axis of rotation A2.
[0030] As shown in FIGS. 2 and 3, stator 10 comprises a stator
cylinder 15; cooling fins 16 fixed to the outer face of stator
cylinder 15; and a whole number or quantity of stator segments 18
arranged about axis of rotation A2 and fixed to the inner face of
stator cylinder 15 by fastening devices (not shown). Cooling fins
16 cool stator cylinder 15 and therefore the whole of stator 10.
More specifically, cooling fins 16 and stator cylinder 15 are made
of heat-conducting material, so the heat produced by Joule effect
and otherwise inside stator 10 is transferred to stator cylinder 15
and from this to cooling fins 16 configured to dissipate it. Each
stator segment 18 comprises windings, and packs of stator
laminations 19 wound with a winding associated with only one stator
segment 18, so that said stator segment 18 can be removed from
stator 10 without interfering with the other stator segments 18.
Stator cylinder 15 covers, protects, and supports stator segments
18. Rotor 11 comprises a rotor cylinder 20; rotor segments 21
arranged about axis of rotation A2; and cooling fins 22 fixed to
the inner face of rotor cylinder 20. Rotor cylinder 20 is made of
nonmagnetic material and, in one embodiment of the present
disclosure, is made of aluminum or aluminum alloy.
[0031] In a variation of the present disclosure, rotor cylinder 20
is made of nonmagnetic material, in particular stainless steel.
[0032] In another variation of the present disclosure, rotor
cylinder 20 is made of nonmagnetic material, in particular
copper.
[0033] In another variation of the present disclosure, rotor
cylinder 20 is made of nonmagnetic material, in particular polymer.
In one such embodiment, the nonmagnetic material includes a
heat-conducting polymer material.
[0034] Cooling fins 22 cool rotor cylinder 20 and therefore the
whole of rotor 11. More specifically, cooling fins 22 and rotor
cylinder 20 are made of heat-conducting nonmagnetic material, so
the heat produced in rotor 11 is transferred to rotor cylinder 20
and from this to cooling fins 22 configured to dissipate it.
[0035] As shown in FIG. 3, each rotor segment 21 comprises a
gripper 23, magnetic guides 24, magnetized modules 25, and bolts
26.
[0036] Gripper 23 extends parallel to and radially with respect to
axis of rotation A2, is fixed to rotor cylinder 20 of rotor 11 by
bolts 26, is made of nonmagnetic material, and, in a non-limiting
embodiment of the present disclosure, is made of aluminum or
aluminum alloy.
[0037] In a variation of the present disclosure, gripper 23 is made
of nonmagnetic material, in particular stainless steel.
[0038] In another variation of the present disclosure, gripper 23
is made of nonmagnetic material, in particular copper.
[0039] In another variation of the present disclosure, gripper 23
is made of a nonmagnetic material, such as a heat-conducting
polymer material.
[0040] In each rotor segment 21, magnetized modules 25 are aligned
radially with respect to axis of rotation A2 (FIG. 2) to form
groups of modules 25, which in turn are arranged successively,
parallel to axis of rotation A2 (FIG. 2), along the whole of rotor
segment 21.
[0041] With particular reference to FIGS. 2 and 3, each group of
modules 25 comprises two modules 25 aligned radially with respect
to axis of rotation A2; and, by way of a non-limiting example, each
rotor segment 21 comprises eleven groups of modules 25 (not shown
in the drawings) arranged successively, parallel to axis of
rotation A2.
[0042] With reference to FIGS. 2 and 3, each group of modules 25 is
located between a respective pair of magnetic guides 24, each
defined by respective packs of laminations made of ferromagnetic
material, to guide the magnetic flux of magnetized modules 25. Each
rotor segment 21 therefore comprises eleven pairs of magnetic
guides 24. Each pair of magnetic guides 24 is located inside
gripper 23, which is fixed to rotor cylinder 20 by bolts 26 and
defines a support for the respective pair of magnetic guides 24 and
the respective group of modules 25. Each pair of magnetic guides 24
has two faces 27, is traversed in use by the magnetic flux of
magnetized modules 25, and defines the field lines. Group of
modules 25 is protected at the top end by two insulating members 28
between magnetic guides 24, and is protected at the bottom end by
an insulating member 28a between magnetic guides 24.
[0043] In electric machine 6 described above, the magnetic flux
defined by the main frequency component of the magnetomotive force
of stator 10 assists in defining the torque of electric machine 6
and converting kinetic to electric energy and vice versa, whereas
the magnetic flux defined by the harmonics of the magnetomotive
force of stator 10 plays no part in defining the torque of electric
machine 6 and merely dissipates energy in heat.
[0044] By virtue of rotor cylinder 20 of nonmagnetic material, the
magnetic flux defined by the harmonics of the magnetomotive force
of stator 10, and which closes in nonmagnetic rotor cylinder 20, is
attenuated (i.e., is not attracted to rotor cylinder 20), as in the
known art, and is reduced with respect to the known art, thus
reducing parasitic currents in rotor 11 and power dissipation.
Moreover, reducing power dissipation also reduces the heat
generated in rotor 11 with respect to the known art.
[0045] In the FIG. 4 variation of the present disclosure, rotor
cylinder 20, fins 22 and grippers 23 are eliminated, and rotor 11
comprises a rotor cylinder 40, arms 41, and cooling fins 42, all
made of nonmagnetic material and formed integrally in one
piece.
[0046] Rotor cylinder 40 extends longitudinally, parallel to axis
of rotation A2. Arms 41 extend radially, with respect to axis of
rotation A2, towards stator 10, and are configured to engage
magnetic guides 24, and more specifically to support magnetic
guides 24 and magnetized modules 25. Arm 41 define supports for
magnetized modules 25.
[0047] Cooling fins 42 extend radially, with respect to axis of
rotation A2, in the opposite direction to arms 41 and towards the
centre of rotor 11, and are configured to dissipate heat from rotor
cylinder 40.
[0048] The nonmagnetic material from which rotor cylinder 40, arms
41 and cooling fins 42 are made is aluminum or aluminum alloy.
[0049] In a variation of the present disclosure, the nonmagnetic
material from which rotor cylinder 40, arms 41 and cooling fins 42
are made is a nonmagnetic material, such as a heat-conducting
polymer material.
[0050] By way of a non-limiting example, rotor 11 of aluminium,
aluminium alloy or polymer material may be extruded to form rotor
cylinder 40, cooling fins 42 and arms 41 simultaneously.
[0051] In a variation of the present disclosure, the nonmagnetic
material from which rotor cylinder 40, arms 41 and cooling fins 42
are made is stainless steel.
[0052] In another variation of the present disclosure, the
nonmagnetic material from which rotor cylinder 40, arms 41 and
cooling fins 42 are made is copper-based.
[0053] Though electric machine 6 described is a radial-flux, buried
permanent magnet type, the protective scope of the present
disclosure extends to any other type of permanent magnet electric
machine, such as radial-flux surface-magnet, or axial-flux, or
cross-flux electric machines. Also, the wind turbine is a
direct-drive type (i.e., in which the hub and electric machine
rotor are connected directly).
[0054] The present disclosure also covers embodiments not described
in the present detailed description, as well as equivalent
embodiments, within the protective scope of the accompanying
Claims.
[0055] That is, changes may be made to the present disclosure
without, however, departing from the scope of the present
disclosure as defined in the accompanying Claims. It should thus be
understood that various changes and modifications to the presently
disclosed embodiments will be apparent to those skilled in the art.
Such changes and modifications can be made without departing from
the spirit and scope of the present subject matter and without
diminishing its intended advantages. It is therefore intended that
such changes and modifications be covered by the appended
claims.
* * * * *